Morphotropic NaNbO_3-BaTiO_3-CaZrO_3 lead-free ceramics with temperature-insensitive piezoelectric properties

摘要

A morphotropic NaNbO_3-based lead-free ceramic was reported to have temperature-insensitive piezoelectric and electromechanical properties (d_(33)= 231 pC/N, k_p = 35%, T_c = 148 ℃, and low-hysteresis strain ～0.15%) in a relatively wide temperature range. This was fundamentally ascribed to the finding of a composition-axis vertical morphotropic phase boundary in which coexisting ferroelectric phases are only compositionally driven and thermally insensitive. Both phase coexistence and nano-scaled domain morphology deserved well enhanced electrical properties, as evidenced by means of synchrotron x-ray diffraction and transmission electron microscopy. Our study suggests that the current lead-free ceramic would be a very promising piezoelectric material for actuator and sensor applications.